Yamada A, et al. - The risk of gastrointestinal cancers in patients with cystic fibrosis was assessed. In this work, there was a significantly increased risk of gastrointestinal cancer, including small bowel, colon, biliary tract, and pancreatic cancers, in patients with cystic fibrosis vs the general population. Findings stress the need for individualized screening strategies for site-specific gastrointestinal cancers in these patients.

Methods

• Researchers performed a systematic review of PubMed, MEDLINE, Google Scholar, Scopus, Embase, and Cochrane databases with no language restrictions for studies published from inception of the databases to Aug 1, 2017, assessing the risk of gastrointestinal cancers in patients with cystic fibrosis.
• Abstracts from scientific meetings and the bibliographies of identified articles were also searched for additional references.
• They included studies if they reported the standardized incidence ratio (SIR) or incidence ratio per person-years.
• They applied no exclusion criteria regarding patient characteristics (age, sex, comorbidities, cystic fibrosis mutation type), study setting (location and time period), or method of reporting cancer diagnoses.
• Risk of gastrointestinal cancer and site-specific gastrointestinal cancers in patients with cystic fibrosis compared with the general population were assessed as the primary outcome measure.
• They calculated pooled summary estimates using a random-effects model, and performed subgroup analyses to establish whether risk of gastrointestinal cancer varied according to patient lung transplant status.

Results

• Researchers recognized 95,681 records in this search; of these, six cohort studies including 99,925 patients (544,695 person-years) were eligible for the meta-analysis.
• Significantly higher risk of gastrointestinal cancer was noted in patients with cystic fibrosis than in the general population (pooled SIR 8·13, 95% CI 6·48–10·21; p < 0·0001; log SIR 2·10, 95% CI 1·87–2·32; p < 0·0001, I²=93·93%).
• Subgroup analyses revealed increased risk of gastrointestinal cancer among patients with cystic fibrosis who had a lung transplant compared with that of patients who did not receive a transplant (pooled SIR 21·13, 95% CI 14·82–30·14; p<0·0001; log SIR 3·05, 95% CI 2·70–3·41; p<0·0001, I²=28·52% vs pooled SIR 4·18, 3·10–5·62; p < 0·0001; log SIR 1·43, 1·13–1·73; p <0 ·0001, I²=22·66%).
• In addition, they noted that patients with cystic fibrosis had significantly increased risk for the following site-specific cancers in comparison to the general population: small bowel cancer (pooled SIR 18·94, 95% CI 9·37–38·27; p < 0·0001; log SIR 2·94, 95% CI 2·24–3·64; p<0·0001, I²=38·61%), colon cancer (10·91, 8·42–14·11; p < 0·0001; log SIR 2·39, 2·13–2·65; p < 0·0001, I²=88·09%), biliary tract cancer (17·87, 8·55–37·36; p < 0·0001; log SIR 2·88, 2·15–3·62; p < 0·0001, I²=10·16%), and pancreatic cancer (6·18, 1·31–29·27; p=0·022; log SIR 1·82, 0·27–3·38; p < 0·0001, I²=62·57%).